THE Duke of Edinburgh has been successfully treated for a blocked coronary artery after being rushed to hospital with chest pains.

The Royal Family’s traditional Christmas celebrations were thrown into chaos last night after Prince Philip collapsed and was taken to hospital from the Sandringham Estate in Norfolk to Papworth Hospital in Cambridge.

An "invasive procedure of coronary stenting" was performed in to the cardiothoracic unit. He will remain in hospital for observation for a short period.

Buckingham Palace said in a short statement: "Following tests at Papworth Cardiothoracic Hospital in Cambridge this evening the Duke of Edinburgh was found to have a blocked coronary artery which caused his chest pains.

"This was treated successfully by the minimally invasive procedure of coronary stenting. Prince Philip will remain in hospital under observation for a short period."

The Duke is expected to be in hospital for the immediate Christmas period and is likely to be visited by some of the royals gathered in the Queen's private estate in Sandringham.

Dr Simon Davies, consultant intervention cardiologist at the Royal Brompton Hospital in London, said Philip may have been on the verge of a heart attack or actually had one before the stenting procedure was performed.

Dr Davies said: "What they have done is they put a miniature sausage-shaped balloon down the artery, pushed the balloon into the narrowed section and then blown it up.

"That forces the material that is blocking the artery outwards and then gets the blood flowing down the artery again."

His 62-mile journey to the UK’s largest specialist cardiothoracic hospital and the country’s main heart and lung transplant centre came just before 6pm.

Philip and the Queen, 85, had arrived in Sandringham on Tuesday for their festive break. They were to be joined by the rest of the Royal Family, including Prince William and wife Kate for a Christmas Day church service followed by a Christmas lunch.

The following day the family traditionally take part in a Boxing Day shoot which Philip usually organises.

A spokeswoman for the East of England Ambulance Service confirmed it was called to the Sandringham Estate at 6pm.

Philip has managed a heart condition for almost 20 years as he bravely ploughed on with his royal duties at the Queen’s side.

He was renowned for being impeccably fit well into his sixties – passing a heart test to renew his pilot licence with nearly top marks when he was 63.

He had a cancer scare in 1996 when he developed a growth on his nose. It was benign and he had it removed.

In 2007 it was reported that he suffered a serious bout of ill-health which caused concern among the Royal Family.

He recovered and afterwards insisted on continuing with a full programme of engagements, refusing to curtail his busy schedule.

The duke, who is patron of the British Heart Foundation, has had to take medication regularly.

His bodyguards are always fully briefed on his heart condition and are under orders to take him to hospital if he becomes dizzy or short of breath.

They have been “instructed” not to take “no for an answer” in those circumstances and contact doctors immediately.

It is thought his busy timetable may have in the past taken a toll on the prince. When it has been suggested he cuts back on his engagements, one aide is reported to have said in the past: “Who is going to tell him? To be blunt, the duke is not somebody you tell what to do.”

He has been for regular check-ups for his heart for more than a decade at London’s King Edward VII Hospital.

In 2008 he was admitted to hospital for treatment for a chest infection. He was taken to the £500-a-night private hospital after he caught a cold and his health deteriorated. On that occasion he was treated by the Physician to the Queen, Harley Street’s Prof John Cunningham.

He also has a prostate condition which he has been treated for at the same hospital.

Checks were carried out on his prostate gland after routine tests which showed high levels of PSA – a protein produced by the prostate and a warning sign for cancer. Since then his health has been under “active surveillance”.

The Prince has had a busy year of engagements, including a jam-packed 10-day visit to Australia with the Queen just two months ago.

As well as accompanying the Queen on most of her official visits, Philip also hosts regular dinners and receptions of his own for the charities and organisations that he is close to.

The Queen and Philip have a busy year planned for 2012 as the Queen celebrates her Diamond Jubilee.

They will be the focus of the main Jubilee celebrations in June and have opted to stay close to home for the rest of the year, carrying out a UK tour while younger members of the family travel abroad.

The hospital where Prince Philip was taken is a world leader in its expertise in heart surgery.

Despite the Queen Elizabeth Hospital in King’s Lynn being only 5.7 miles from Sandringham, Philip was taken the 62 miles to Papworth Hospital in Cambridge because of the superior care on offer.

Papworth describes itself as the UK's largest specialist cardiothoracic hospital and the country's main heart and lung transplant centre.

It treats more than 22,800 inpatient and day cases and 53,400 outpatients each year from across the UK. Its services include cardiology, respiratory medicine, and cardiothoracic surgery and transplantation.

The cardiac unit there performs more major heart operations than any other unit in the UK - around 2,300 per year.

According to their website, the unit specialises in “complex” heart conditions and provides a service offering operations to “high-risk patients...especially in the elderly”.

Survival rates are amongst the best in the UK with 98 per cent of patients undergoing successful operations this year alone. It was also home to the first successful heart transplant in the UK.

Stephen Bridge, Chief Executive of Papworth Hospital said: “Patients choose to come to Papworth because, as an international centre of excellence, we are able to attract the best, most highly skilled staff and deliver the very best results for our patients.”

Sam Nashef, consultant cardiac surgeon, said that Papworth was a world leader when it came to heart surgery.

Mr Nashef said: “Heart surgery in the UK is now so good that, as a whole, British hospitals have death rates which are consistently lower...but even taking this into account cardiac surgery mortality at Papworth this year was less than half the expected mortality in comparison with the most recent British results.”

Dickie Arbiter, a former press secretary to the Queen, said: "The Duke of Edinburgh's health is actually pretty good given that he is 90."

"He has had these chest pains before and I don't think it's anything untoward, but given his age they are being safe rather than sorry.

"I am sure we are going to see him on Christmas Day and he can look forward to accompanying the Queen in the new year." Margaret Holder, a royal commentator, said: "It's obviously very worrying for the Queen and the rest of the Royal Family who are gathering at Sandringham for Christmas.

"It might not be as serious as it sounds, it's possible it could be a bit of indigestion and they are just checking it over, let's hope it's something simple like that.

"But he is 90, he has been in remarkable health. For somebody who has just done an 11-day tour of Australia at 90, that's amazing in itself as it is.

"A lot of people that age could not even manage to deal with the long flights there and back. I think it might have taken something out of him, I think they are pushing him to the limits doing that."

Former BBC royal correspondent Jennie Bond said the news was "very sad" and "clearly disruptive" for their family Christmas.

She said: "Either this is more serious and therefore they felt they really must issue a statement, or they've simply moved with the times and it's going to get out in social media."

Dr Simon Davies, consultant intervention cardiologist at the Royal Brompton Hospital in London, said: "I think the fact is there are many causes of chest pain.

"Some of them have very distinctive characteristics but some are rather vague. That's the diagnostic problem.

"The first thing to think about is who is having the pain. You just have to be suspicious that it's the heart just because he is a man and he is 90.

"The second part of the diagnostic process is tests."

He said these were likely to include an electrocardiogram (ECG), which records the rhythm and electrical activity of the heart, and blood tests.

The cardiologist said it was "impossible to say" how long Philip could be kept in hospital.

But he added: "The fact is he must have looked after himself to be looking so well."